Cyanines comprising either a benzo[e]‐ or benzo[c,d]indolium core facilitate initiation of radical photopolymerization combined with high power NIR‐LED prototypes emitting at 805 nm, 860 nm, or 870 nm, while different oxime esters function as radical coinitiators. Radical photopolymerization followed an initiation mechanism based on the participation of excited states, requiring additional thermal energy to overcome an existing intrinsic activation barrier. Heat released by nonradiative deactivation of the sensitizer favored the system, even under conditions where a thermally activated photoinduced electron transfer controls the reaction protocol. The heat generated internally by the NIR sensitizer promotes generation of the initiating reactive radicals. Sensitizers with a barbiturate group at the meso‐position preferred to bleach directly, while sensitizers carrying a cyclopentene moiety unexpectedly initiated the photosensitized mechanism.

NIR‐sensitized cationic polymerization proceeded with good efficiency, as was demonstrated with epoxides, vinyl ether, and oxetane. A heptacyanine functioned as sensitizer while iodonium salt served as coinitiator. The anion adopts a special function in a series selected from fluorinated phosphates ( a : [PF 6 ] − , b : [PF 3 (C 2 F 5 ) 3 ] − , c : [PF 3 ( n ‐C 4 F 9 ) 3 ] − ), aluminates ( d : [Al(O‐ t ‐C 4 F 9 ) 4 ] − , e : [Al(O(C 3 F 6 )CH 3 ) 4 ] − ), and methide [C(O‐SO 2 CF 3 ) 3 ] − ( f ). Vinyl ether showed the best cationic polymerization efficiency followed by oxetanes and oxiranes. DFT calculations provided a rough pattern regarding the electrostatic potential of each anion where d showed a better reactivity than e and b . Formation of interpenetrating polymer networks (IPNs) using trimethylpropane triacrylate and epoxides proceeded in the case of NIR‐sensitized polymerization where anion d served as counter ion in the initiator system. No IPN was formed by UV‐LED initiation using the same monomers but thioxanthone/iodonium salt as photoinitiator. Exposure was carried out with new NIR‐LED devices emitting at either 805 or 870 nm.

Four new complexes 4) (2-HFBA: 2-fluorobenzoic acid; 4,4Ј-bpy: 4,4Ј-bipyridine; 2,2Ј-bpy: 2,2Ј-bipyridine; phen: 1,10-phenanthroline) have been synthesized and characterized by X-ray diffraction analysis. Complex 1 is a dimeric molecule with a one-dimensional supramolecular structure formed by hydrogen bonds. Complex 2 is an infinite one-dimensional polymer chain formed by bridging carboxylato groups; its 2D framework structure is formed by hydrogen bonds. The structure of complex 3 contains three independent binuclear molecules in the asymmetric unit. In two of them, two Tb 3+ ions are held together by four 2-FBA groups, with two of them in a bidentate-bridging mode and the other two in a chelating-bridging mode. In the third, two Tb 3+ ions are held together by four 2-FBA groups, all of which are in the bidentate-bridging mode. One 2-FBA group and one 2,2Ј-bpy chelate to one Tb 3+ ion, resulting in coordination numbers of the central ter-

No abstract

No abstract